It is known to provide a band which is adapted to encircle a tooth being filled to support weak walls of the tooth following drilling against the outward forces which are applied during the compression of the filling material into the cavity drilled in a tooth. Such bands are most frequently used to define the outer wall of the cavity when the cavity drilled into the tooth extends to any lateral surface thereof.
Such bands are frequently called matrix bands, are wholly composed of a noncorroding metal such as stainless steel, and have frequently been designed for repeated use.
In the preparation of a tooth which has deteriorated or been the subject of caries, it is a common practice, utilizing dental drills, to remove the deteriorating or deteriorated material to clean enamel and thereby form an undercut cavity of the type described. When the cavity opens solely at the chewing surface of the tooth, the use of a matrix band is not necessary. When, however, the cavity extends to a lateral portion of the tooth, such a matrix band can be applied to define a lateral wall of the cavity into which the filling is forced so that the filling will lie generally flush with the lateral edges of the cavity.
Various matrix bands have been provided heretofore to ensure the correct bite for teeth being repaired, to support the tooth against the mechanical working which ensures the effective strength of amalgam fillings and to separate one filling from another or the filling material of one tooth from an adjacent tooth.
While such matrix bands have been provided in a variety of sizes and shapes, they all are generally associated with a tightening mechanism, generally utilizing screw or wind-up principles, which is normally left in the mouth or may be part of a tool withdrawn from the mouth and which, upon tightening, draws the ends of the band toward one another to tighten the band around the tooth.